title: Increased risk of pneumonia among ventilated patients with traumatic brain injury: every day counts!
abstract: BACKGROUND
  Patients with traumatic brain injury (TBI) frequently require mechanical ventilation (MV). The objective of this study was to examine the association between time spent on MV and the development of pneumonia among patients with TBI.
  
  
  METHODS
  Patients older than 18 y with head abbreviated injury scale (AIS) scores coded 1-6 requiring MV in the National Trauma Data Bank 2007-2010 data set were included. The study was limited to hospitals reporting pneumonia cases. AIS scores were calculated using ICDMAP-90 software. Patients with injuries in any other region with AIS score >3, significant burns, or a hospital length of stay >30 d were excluded. A generalized linear model was used to determine the approximate relative risk of developing all-cause pneumonia (aspiration pneumonia, ventilator-associated pneumonia [VAP], and infectious pneumonia identified by the International Classification of Disease, Ninth Revision, diagnosis code) for each day of MV, controlling for age, gender, Glasgow coma scale motor score, comorbidity (Charlson comorbidity index) score, insurance status, and injury type and severity.
  
  
  RESULTS
  Among the 24,525 patients with TBI who required MV included in this study, 1593 (6.5%) developed all-cause pneumonia. After controlling for demographic and injury factors, each additional day on the ventilator was associated with a 7% increase in the risk of pneumonia (risk ratio 1.07, 95% confidence interval 1.07-1.08).
  
  
  CONCLUSIONS
  Patients who have sustained TBIs and require MV are at higher risk for VAP than individuals extubated earlier; therefore, shortening MV exposure will likely reduce the risk of VAP. As patients with TBI frequently require MV because of neurologic impairment, it is key to develop aggressive strategies to expedite ventilator independence.
authors.affiliation: Department of Surgery, Center for Surgical Trials and Outcomes Research, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
authors.forename: Xuan
authors.initials: X
authors.lastname: Hui
authors.forename: Adil H
authors.initials: AH
authors.lastname: Haider
authors.forename: Zain G
authors.initials: ZG
authors.lastname: Hashmi
authors.forename: Amy P
authors.initials: AP
authors.lastname: Rushing
authors.forename: Nitasha
authors.initials: N
authors.lastname: Dhiman
authors.forename: Valerie K
authors.initials: VK
authors.lastname: Scott
authors.forename: Shalini
authors.initials: S
authors.lastname: Selvarajah
authors.forename: Elliott R
authors.initials: ER
authors.lastname: Haut
authors.forename: David T
authors.initials: DT
authors.lastname: Efron
authors.forename: Eric B
authors.initials: EB
authors.lastname: Schneider
mesh_terms: D000328:Adult; D000368:Aged; D001930:Brain Injuries / Q000453:epidemiology*; D015897:Comorbidity; D016208:Databases, Factual / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053717:Pneumonia, Ventilator-Associated / Q000453:epidemiology*; D011237:Predictive Value of Tests; D012121:Respiration, Artificial / Q000009:adverse effects* / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D015599:Trauma Severity Indices; D055815:Young Adult
keywords: Mechanical ventilation; Pneumonia; Trauma; Traumatic brain injury